PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA 91109. TELEPHONE (818) 354-5011

PHOTO CAPTION                                             P-43895
                                                   April 13, 1994
                                                   Manaus, L-band

This false-color L-band image of the Manaus region of Brazil was 
acquired by the Spaceborne Imaging Radar-C and X-Band Synthetic
Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour
on orbit 46 of the mission.  The area shown is approximately 8
kilometers by 40 kilometers (5 by 25 miles).  At the top of the
image are the Solimoes and Rio Negro rivers just before they
combine at Manaus to form the Amazon River.  The image is
centered at about 3 degrees south latitude, and 61 degrees west
longitude.  The false colors are created by displaying three L-
band polarization channels; red areas correspond to high
backscatter at HH polarization, while green areas exhibit high
backscatter at HV polarization.  Blue areas show low returns at
VV polarization; hence the bright blue colors of the smooth river
surfaces.  Using this coloring scheme, green areas in the image 
are heavily forested, while blue areas are either cleared forest
or open water.  The yellow and red areas are flooded forest.
Between Rio Solimoes and Rio Negro a road can be seen running
from some cleared areas (visible as blue rectangles north of Rio
Solimoes) north towards a tributary of Rio Negro.

                              -----

Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-
C/X-SAR) is part of NASA's Mission to Planet Earth.  The radars 
illuminate Earth with microwaves allowing detailed observations
at any time, regardless of weather or sunlight conditions.  SIR-
C/X-SAR uses three microwave wavelengths:  L-band (24 cm), C-band
(6 cm) and X-band (3 cm).  The multi-frequency data will be used
by the international scientific community to better understand
the global environment and how it is changing.  The SIR-C/X-SAR
data, complemented by aircraft and ground studies, will give
scientists clearer insights into those environmental changes
which are caused by nature and those changes which are induced by
human activity.  SIR-C was developed by NASA's Jet Propulsion
Laboratory.  X-SAR was developed by the Dornier and Alenia 
Spazio companies for the German space agency, Deutsche Agentur
fuer Raumfahrtangelegenheiten (DARA), and the Italian space
agency, Agenzia Spaziale Italiana (ASI).

                              #####